Video: Should married couples combine finances?

Tonight, we begin our week-long series: The State of Our Unions —a look at marriage in this country, and the social winds that are shaping it. Marriage, of course, is largely about combining assets — money.

Husbands and wives argue about money more than they do about sex. But a new generation of couples — like Brett and Alyssa Malinski — is changing the rules. Having lived on their own, they bring their own savings and spending habits and will keep separate bank accounts through their first year of marriage.

"Just getting married was a big adjustment to get used to," says Alyssa Malinski. "We wanted to take baby steps."

More than a third of married women now have some kind of checking or brokerage fund of their own. Some, like Gina Kwok stash money away in secret.

Psychiatrist Dr. Gail Saltz says it's because women now earn more, marry later in life and worry about a 50 percent divorce rate.

"What's mine is mine, and maybe what's yours is mine, too," says Saltz, associate professor of psychiatry at New York Presbyterian Hospital.

It's not romantic, but we're talking about a generation raised on equality. Keeping money separate means husbands never get to ask, "You paid how much for those shoes?" Some financial planners, like Elissa Buie, say the changing attitudes are risky.

"So we're learning this anew," says Buie. "We haven't had role models for it." She warns couples to manage at least some money together, which is what the Malinskis are now working on.